The present invention relates to a device to improve a loudspeaker enclosure duct and more particularly, the present invention relates to a device for the transfer of low frequency energy from within the speaker enclosure to the exterior of the enclosure.
Loudspeaker technology in the prior art has proposed many devices and methods to enhance sonic performance. One of the most important frequency ranges is the low end range between 30 Hz and 100 Hz. This frequency range is often delivered from a loudspeaker enclosure through an opening in the front baffle of the enclosure. As such, much of the sound at this frequency remains trapped within the enclosure leading to degradation of the overall sound experienced by the listener.
Other arrangements in known loudspeakers provide a conduit or port extending within the enclosure to the opening. Although generally useful, these devices do not substantially augment the output of the lower frequencies.
One object of the present invention is to provide an arrangement for enhancing the electromotive properties of a loudspeaker port to improve the transfer of low frequency sound energy from within the loudspeaker enclosure to a listening area.
A further object of the present invention is to provide a device for enhancing the quality of low frequency sound exiting a loudspeaker port, comprising:
a waveguide adapted to be coupled to a loudspeaker duct, the waveguide having a hollow enclosed body composed of a rigid and nonresonant material and including a plurality of slots in the body, whereby the slots present mechanical impedance to low frequency sound waves passing through the body for increasing the transfer of the sound waves from within a loudspeaker enclosure through the port.
The waveguide may comprise any suitable material of a rigid, nonresonant form. Examples include paperboard, plastic, metal, composite materials among others. Rigidity is desirable to reduce tonal coloration to the sound waves which would otherwise degrade sonic quality.
A further object of one embodiment of the present invention is to provide a device for enhancing the quality of low frequency sound exiting a loudspeaker port of a loudspeaker comprising in combination:
a loudspeaker having an enclosure, speakers and a port for the passage of low frequency sound waves from within the enclosure to a point exterior thereof, the port including a hollow duct extending therefrom for transferring the low frequency sound waves from within the enclosure to the port; and
a waveguide coupled to the duct, the waveguide having a hollow enclosed body composed of a rigid and nonresonant material and including a plurality of slots in the body, whereby the slots present mechanical impedance to the low frequency sound waves passing through the body for increasing the transfer of the sound waves from within a loudspeaker enclosure through the port.
The shape of the waveguide is not a critical feature; any hollow enclosure shape may be employed. With respect to the slots, the position these occupy on the waveguide may take any pattern.
In terms of specific dimensions, the waveguide dimensions will vary depending on the size (internal volume of the loudspeaker enclosure).
A still further object of one embodiment of the present invention is a device for enhancing the quality of low frequency sound exiting a loudspeaker port of a loudspeaker comprising, in combination:
a loudspeaker having an enclosure, speakers and a port for the passage of low frequency sound waves from within the enclosure to a point exterior thereof;
a waveguide, the waveguide having a hollow enclosed body composed of a rigid and nonresonant material and including a plurality of slots in the body; and
a hollow duct coupled to the waveguide and to the port for transferring the low frequency sound waves from within the enclosure to the port, whereby the slots present mechanical impedance to the low frequency sound waves passing through the body for increasing the transfer of the sound waves from within a loudspeaker enclosure through the port.
Having thus described the invention, reference will now be made to the accompanying drawings illustrating preferred embodiments.